
Class. 
Book. 



TSu'^O 



V^y- 



Gopyiight]^^. 



COPYRIGHT DEPOSIT. 



"GRADES OF STEEL" 

By H. P. PARROCK, s. B. 



To L. B. 



A 



■7° 



? 



n^ 



INTRODUCTORY 



This booklet aims to instruct the machinist and the tool 
maker, the final users of tool steel — the men upon whom the ulti- 
mate economies depend. The object in giving the various open 
hearth analyses is to indicate the careful selection that is made for 
various purposes and to show the grades that lead up to the cru- 
cible steels. 

Economy in steel is becoming more and more necessary, and 
probably no commodity of so much importance has been so grossly 
wasted. If it pays to select grades at $30.00 per ton it surely pays 
to choose carefully at $3000.00 per ton, however relatively small the 
more expensive item may be. 

The author believes that the care in manufacture that this 
booklet merely indicates will help the machinist and tool maker 
toward an attitude of economy in the use of steel that will be of 
value to them individually, and to men higher up. 



©GI.A-^^-819 



ft-l^^l"^. 



The author wishes to acknowledge 
the use of data from ''On the Art of 
Cutting Metals," by F. W. Taylor and 
from the catalog of The Shore Instru- 
ment & Mfg. Co. The courtesy and 
kindness of Mr. Taylor and Mr. Shore 
is appreciated. 



COPYRIGHTED 1910 
H. P. PARROCK 



METHODS OF MANUFACTURE 



steel is, in general, made by one of the following processes: 
"Bessemer" — in which air, usually in its natural condition, is 
blown through molten pig metal until (in the acid process) the 
manganese, silicon and carbon are practically burned out. Silicon, 
oxidizing to SiO^, furnishes most of the heat for the process. The 
"blow" is continued until a metal hot enough to handle in ladles 
is obtained, when the product is poured as steel, various additions 
of ferromanganese, spiegel, or other metalloids, or carbon being 
made, in the ladle, to give the whole the desired chemical and phy- 
sical properties. In the United States, all Bessemer converters are 
"acid." 



WQSE 

lAiciiis/eo -cfi, a&tl 







CUT 1 



BESSEMER CONVERTER 



(parrock) 



Cross section through trumnions; capacity about 15 tons per heat; 
3 to 5 heats per hour. Bessemer Converters are installed usually 
in batteries of two, often of three or four. 



"Open Hearth" — in which pig iron, or steel, or both, cold or 
molten, with iron ore, are melted in a furnace suitably built of 
refactory materials, by the action of a flame produced by coal gas 
or oil or natural gas. The heat for the process is derived mainly 
from the flame supplied. The process is continued until at the 
right temperature for pouring, the approximate chemical and phy- 
sical conditions will result in the finished material, additions of fer- 
romanganese, ferro-phosphorus, or other metalloids, or carbon 
being made, generally as the heat goes into the ladle. Lime is 
included with raw materials when the hearth or bottom of the 
furnace is made of dolomite, lime, or magnesite. the furnace 
and its product being designated as "basic"; steel made on a 
hearth of sand, and the furnace as well, is known as ' * acid. ' ' The 
use of regenerating chambers (checkers) and reversing valves for 
the fuel and air is demanded by the nature of the process and the 
intense heat desired. 



PIPE. Fan 
ail ofl 
ens ^ 




CUT 2 



(parrock) 



OPEN HEARTH FURNACE— (Basic) 



Capacity 52 tons per heat. 

Arranged to use oil or natural gas, the arch being omitted over the gas 
"up take." Oil or natural gas is piped as indicated; producer gas, 
when used, enters through "gas" chambers. All waste gases pass 
out through both chambers. Open hearth furnaces are installed 
usually in groups of 10 to 12, to form one unit. 

8 



"Duplex" — in which metal from which silicon has been blown, 
or burned out, in the Bessemer process, is transferred while molten 
to an Open Hearth furnace, usually "basic." This process was 
invented to overcome the disadvantage of ores high in phosphorus, 
sulphur and silicon, when it was desired to convert such ores into 
steel. 

"Transfer" — in which steel sufficiently cleansed of phos- 
phorus and sulphur, in a "basic" open hearth furnace, is trans- 
ferred in a ladle, to an "acid" open hearth furnace where the 
metal is handled as an "acid" heat, and so accepted when finished 
and inspected. The "Duplex" and "Transfer" processes are 
modifications or combinations of "Bessemer" and "Open Hearth." 

"Crucible" — in which steel or iron, or both, generally in var- 
ious stages of previous refinement, with charcoal, or tungsten, or 
chrome or vanadium or other "alloys," or any of them, are melted 
in a crucible of clay, or graphite. The crucibles are covered, en- 
closing the metal, and are placed in the path of a flame produced 
by coal, oil, or gas, or directly on a bed of fuel, preferably coke or 
anthracite. The metals derive heat through the walls of the cru- 
cible; the flame does not come in contact with the metal. Heat 
is applied to the crucible until, passing through various stages, the 
metal attains the proper temperature and condition for pouring. 




CUT 3 



CRUCIBLE PITS 

Capacity 100 pounds per pot. 

The fuel in this case is anthracite coal. 



(parrock) 



Bessemer converters are ganerally of 10 to 20 tons capacity; 
a heat is blown in 8 to 20 minut-ee; the depth of metal in the bath 
varies from 12" to 26". 

Open hearth furnaces vary iij capacity from 5 to 250 tons, de- 
pending upon the requirements and some modifications of the 
process. The usual capacity is 50 to 60 tons, the depth of the bath 
18" to 24". The time required to melt a heat is 5% to 12 hours, 
depending upon the mixture, the construction of the furnace, the 
fuel, the melter and the product desired. 

Crucible pots generally hold 100 to 125 pounds of material. 
The time required in melting, killingj pulling and pouring runs from 
214 to 5 hours. 

Bessemer steel is in demand for rails, sheet bars, pipe, struc- 
tural shapes, bars, bolts, nut and screw steel and the cheaper 
forms of steel products. Bessemer steel replaced commercial iron 
and is in turn being succeeded by open hearth steel. Open hearth 
steel is used for structural shapes, rails, sheet bars, forgings, rivets, 
springs, axles, nuts, bolts, screws, castings, and bars for all pur- 
poses to which steel is put. It is used to make cutting tools of 
the cheaper forms, and frequently for remelting purposes by makers 
of crucible steels. 

Crucible steel is demanded for cutting tools, dies, fine springs 
and all the more expensive articles for which steel is available. 
Important levers, piston rods, shafts, gears, files of the better 
grade, hammers, surgical instruments, cutlery, knives, razors, etc., 
are made of crucible steels. 

Eapid advance is being made in the manufacture of steel by 
the electrical process; one furnace of 15 tons capacity, in this 
country, is said to have turned out 17 heats in 24 hours. This 
furnace receives partly converted metal, continuing the purifica- 
tion, much as in the "Duplex" process. The possibilities of elec- 
tric melting are far reaching and the development of the process 
is being watched by all metallungists. 



10 



VARIOUS GRADES OF STEEL 

In order to indicate the variety of steels specified and used for 
various purposes, and show the relation between open hearth and 
crucible steels, so far as analyses go, the following data is offered. 
The open hearth analyses are taken from personal notebooks and the 
comments are based on observation. Bessemer steel analyses are 
not offered, since in all cases, open hearth steels are made to re- 
place them, and further since they do not greatly interest users 
of tool steels. All of the following analyses are of open hearth 
steels, "basic" or "acid" as indicated; the crucible analyses 
when given later, are designated "crucible." 

The following abbreviations are used throughout: 

T, S. Tensile strength, in pounds per square inch. 

E. L. Elastic limit, in pounds per square inch. 



E. 


R. Elastic ratio, %. 




S. Sulphur %. 






El, 


, Elongation 


, % in 8". 




Si. Silicon %. 






E. 


A. Eeduction of Area 


, % 


Cu. Copper %. 






C. 


Carbon %. 






Mo. Molybdenum 


%. 




Mn. Manganese %. 




Va. Vanadium % 


. 




P. 


Phosphorus 


%. 




W. Tungsten %. 
Cr. Chromium %. 






Table ( 


:i) 


DEAD SOFT BASIC 






T.S. 


C. Mn. 


P. 


s. 


Si. E.R. 


El. 


R.A. 


44710 


.04 .15 


.008 


.030 


Low 57 


28 


50 


45230 


.05 .12 


.003 


.024 


To 


To 


To 


44930 


.06 .12 


.011 


.025 


64 


30 


58 


45390 


.035 .10 


.008 


.022 


> 1 






45520 


.04 .14 


.007 


.020 


4 < 







For — Soft rivets, wire, seamless drawn tubing, lapweld pipe, 
chain, cold drawing, stamping and pressing, soft machinery bars 
and stay bolts; flanging plate, boiler plate, etc. (Table (2) shows 
a better steel for seamless drawn tubing. Soft steels work best at 
a very high rolling or forging heat. Heat thoroughly ai;d very hot. 
These steels take the maximum amount of draft but show a tend- 
ency to minute surface seams. They should be "chipped" care- 
fully in the billet when used to make stamping plate). 

II 



Table 


(2) 






SOFT BASIC 








T.S. 


0. 


Mn. 


P. 


s. 


SI 


E.R. 


El. 


R.A. 


49150 


.09 


.35 


.007 


.030 


Low 


58 


28 


50 


49080 


.09 


.43 


.008 


.032 


* 4 


To 


To 


To 


50350 


.09 


.48 


.011 


.025 


t I 


64 


30 


68 


49280 


.09 


.39 


.008 


.032 


" 









50920 .10 .45 .020 .031 " 

For — Bridge and ship rivets, seamless drawn tubing, lap weld 
pipe, cold stamping, pressing, flanging, drawing, stay bolts, ties, 
boiler plate, chain, metal wheels, wagon tires, crane bridges, etc. 
For soft bars and special struatural shapes, where great strength 
is not required. (Copper should be kept below .20% in steels sub- 
ject to very hot working, as in drawing seamless tubing. Copper 
is generally conceded to have little action on the physical proper- 
ties of cold steel, and is in general, disregarded. It does have a 
bad effect in hot-working all open hearth steels when present up to 
,60% accompanied by high sulphur and in seamless drawn tubing 
when present up to .30%. Tt sliows up in the first drawing). 



Table 


(3 


) 






TUBING 
"Basic" 








T.S. 




C. 


Mn. 


P. 


S. Si 


E.R. 


El. 


R.A. 


51200 




.11 


.41 


.007 


.022 Low 


58 


28 


50 


51080 




.095 


.54 


.007 


.026 


To 


To 


To 


51370 




.11 


.48 


.009 


.031 


64 


30 


58 


50350 




.09 


.48 


.011 


.025 








51950 




.085 


.46 


.012 


.024 









For — Seamless drawn tubing, lap-weld pipe, boiler, bridge and 
ship rivets, chain, wagon tire, soft machinery bars, cold drawing 
and stamping, wire, stay-bolts, tins, etc. A stiffer steel than Soft 
Basic. Suitable for structural shapes not requiring great stiffness. 
A good steel to subject to shock, as in cranes, presses, etc. For 
boiler and tank plate; very easily flanged. 



12 



Table (4) 



T.S. 









TIN BAR 








"Basic" 


c. 


Mn. 


P. 


S. Si. 


.13 


.44 


.076 


.034 Low 


.10 


.45 


.089 


.034 


.10 


.43 


.074 


.043 


.10 


.44 


.080 


.036 


.12 


.42 


.088 


.029 



E.R. 



EI. 



R.A. 



The high phosphorus prevents "sticking" during the process 
of making sheets. The phosphorus is added ag ferro-phosphorus as 
the heat goes into the ladle. This is generally considered a special 



steel. It is suitable for bolts, 
means from a trace to .03%). 



line pipe, etc. ("Low" Silicon 



Table 


(5] 


1 






RIVET 

"Basic" 










T.S. 




c. 


Mn. 


P. 


S. 


Si. 


E.R. 


El. 


R.A. 












Under 








.54470 




.15 


.36 


.007 


.035 


.05 


58 


28 


."in 


53020 




.12 


.45 


.007 


.024 


t • 


To 


To 


To 


52520 




.12 


.42 


.010 


.031 


• • 


64 


30 


53 


53780 




.14 


.52 


.007 


.027 


■ « 








55tJ70 




.14 


.46 


.007 


.030 


« • 









For — Bridge and ship rivets, seamless drawn tubing, expanded 
metal, pipe skelp, structural shapes for small work, nuts, bolts 
tank plates, boiler plate, etc., fire box plate. (For any grade of 
rivet steel the largest size rivet is best made of the softest steel, 
within the allowable range. That is, make 1%" rivets from bars 
of the 3rd heat; %" of the 5th heat). 



13 



Table (6) 



NUT AND SCREW STEEL 
"Basic" 



T.S. 


C. 


Mn. 


P. 


S. 


E.R. 


El. 


B.A. 




55000 


.12 


.68 


.012 


.124 


54 


25 


45 


Nut 




.14 


.65 


.030 


.132 


To 


To 


To 


' ' 


To 


.18 
.17 


.62 
.69 


.060 
.066 


.072 
.065 


60 


30 


55 


Bolts 

t t 


70000 


.21 


.62 


.058 


.078 








Screws 



The bigh phosplionis and svilphnr facilitate threading, due to 
the easy snapping of the particles before the dies. The tendency 
of the soft steel to curl and choke the dies is reduced to a mini- 
mum. This steel should be worked either very hot or very cold; 
preferably very hot for ease in rolling. These are the grades 
for the commercial nut or bolt steel. Any of the preceeding steels, 
except "Tin Bar" would be suitable for braces, nuts, heavy bolts, 
tie rods, etc., where ease of threading would have to be sacrificed 
to safety. These are special steels, designed to help the machinist. 
Phosphorus is kept low for a certain class of bolts where ability 
to resist shock is important. 



Table 


(7) 


1 






RIVET 
"Basic" 










T.S. 




c. 


Mn. 


P. 


s. 
u 


Si. 
nder 


E.R. 


EI. 


R.A. 


60830 




.19 


.50 


.007 


.028 


.05 


54 


25 


45 


62340 




.20 


.48 


.014 


.029 


1 4 


To 


To 


To 


59970 




.17 


.57 


.007 


.032 


t 4 


60 


30 


55 


69920 




.19 


.56 


.007 


.031 


t ■ 








61740 




.18 


.56 


.007 


.030 


« 1 









For — Bridge and ship rivets of high grade, where stiffness is 
wanted. For bars, nuts, bolts, wire, shafting, spikes, tank plates, 
splice bars, tie plate. For structural shapes for cranes, bridges 
and machinery exposed to shock. This is a good 58-62000 T. S. 
specification for bridge shapes, cable wire, etc. A very good steel 
for all structural work. For: flanging, and boiler plate. 

14 



Table (8; 


1 






STRUCTURAL 
















"Basic 


»» 








T.S. 


C. 


Mn. 


P. 


s. 


Si. 
Under 


E.R. 


El. 


R.A. 


64060 


.23 


.52 


.012 


.031 


.05 


50 


23 


45 


64112 


.23 


.57 


.007 


.036 


• « 


To 


To 


To 


65100 


.22 


.61 


.010 


.029 


« 4 


60 


29 


55 


65460 


.24 


.57 


.008 


.034 


t4 








66080 


.22 


.61 


.010 


.029 


1 • 









For — Bridges, structural shapes of all kinds, machinery steel, 
very soft forgings, hammer work, tank plates, drop forgings, boiler 
plate, tie plate, splice bars, bars for reinforcing concrete, etc. 
(This grade corresponds to a .10%-. 13% carbon acid bessemer in 
tensile strength. Most of the commercial bars in service are rolled 
from this grade or those slightly softer. This table is typical of 
60-70,000 T. S. basic open hearth steel and is suitable for rigid 
constructions with a factor of safety of 4 to 6. This is the upper 
limit for ordinary boiler plate). 



Table (9) 



HARD STRUCTURAL 
"Basic" 



T.S. 


C. 


Mn. 


P. 


S. 


Si. 
¥nder 


E.R. 


El. 


R.A. 


74560 


.34 


.38 


.007 


.026 


.05 


50 


20 


85 


70430 


.28 


.40 


.025 


.05S 


4 1 


To 


To 


To 


72650 


.34 


.55 


.013 


.055 


« 4 


60 


30 


45 


69480 


.28 


.42 


.008 


.037 


f « 








72010 


.27 


.64 


.015 


.045 


44 









For — Large bridges not subjected to heavy shocks. 

For — Special structures requiring stiffness; shafting, beams, 
channels, bars for reinforcing concrete, stiff plate, etc. This grade 
represents the upper limit of tensile strength in structural work. 
This steel requires care in handling, especially in heating. 



13 



Table 


(10) 




SOFT FORGING 










"Acid" 


T.S. 


c. 


Mn. 


P. 


S. Si. 


56290 


.13 


.49 


.035 


.034 .10 


58060 


.16 


.43 


.042 


.049 To 


55740 


.12 


.41 


.032 


.048 ,15 


60180 


.15 


.43 


.034 


.050 


61370 


.15 


.47 


.044 


.054 



Elongation in 2" over 30. 
Reduction of area over 35. 

For — Soft forgings, solid or hollow, no thickness over 10". For 
structural shapes, ship angles, beams, channels, merchant bars, 
shafting, splice bars, tie plate, etc. (All forging steel needs careful 
heat treatment. Hammer work requires that the heat in a piece of 
steel be uniform throughout or bad shrinkage stresses will he set 
up. To offset these stresses, in part, annealing is resorted to; but 
annealing will not entirely remedy bad heating and working). 



Table 


(11) 






FORGING 

"Acid" 


T.a. 


C. 


Mn. 


P. 


S. 


71960 


.25 


.53 


.026 


.048 


68160 


.25 


.41 


.029 


.033 


69260 


.25 


.68 


.036 


.039 


72850 


.25 


.55 


.045 


.049 


72010 


.27 


.64 


.015 


.045 



Si. 
11 



Elongation in 2" over 24. 
Reduction of area over 30. 

For — Large forgings having over 18" thickness of section. 

For — Stiff structural work, stiff wire for suspension work, re- 
inforcing bars, drop-forgings for small stiff work; small engine 
forgings, tin mill screws and boxes, stiff tank plate. 



16 



Table (12) 




MEDIUM FORGING 










"Acid" 




T.S. 


C. 


Mn. 


P. 


s. 


Si. 


82780 


.32 


.46 


.022 


.036 


.10 


80220 


.33 


.60 


.042 


.047 




76040 


.29 


.49 


.034 


.048 


.15 


82780 


.32 


.46 


.022 


.036 


.10 


83820 


.327 


.58 


.029 


.037 


.23 



ElongBtion in 2" over 22. 
Reduction of area over 30. 

For — Solid and hollow forgings of thickness of metal of 12" 
and under; locomotive rods, axles, crank webs, link pins, piston 
rods, engine forgings, propeller shafts, etc. 

For — Large forgings, light rails, cut gears, reinforcing bars, 
hot shear blades, etc., tin mill screws and boxes. 



Table 


(13) 




HARD FORGING 










"Acid" 




T.S. 


0. 


Mn. 


P. 


s. 


Si. 


97320 


.472 


.53 


.039 


.047 


.19 


97610 


.439 


.53 


.027 


.051 


.21 


94230 


.491 


.54 


.029 


.045 


.31 


92610 


.430 


.48 


.025 


.043 


.23 


94480 


.447 


.44 


.022 


.040 


.17 



Elongation in 2" over 10. 
Reduction of area over 45. 



For — Oil tempered forgings up to 4" thickness. For engine 
forgings, locomotive tires, crank pins, webs, crank rods, piston 
pins and rods, and shear blades for hot work; heavy rails, cut 
gears, etc. For very heavy hot die work, drop forging dies, etc., 



tin mill screws, boxes. 



17 



Table (14) 




VERY HARD FORGING 










"Acid" 




T.S. 


C. 


Mn. 


P. 


s. 


Si. 


113580 


.535 


.59 


.029 


.048 


.24 


112550 


.602 


.49 


.016 


.040 


.18 


110580 


.58 


.53 


.018 


.040 


.19 


105700 


.50 


.53 


.020 


.031 


.19 


105680 


.48 


.52 


.012 


.02f8 


.20 



Elongation in 2" over 16. 
Reduction of area over 45. 

For — Oil tempering and very hard stiff forgingg. 

For — Freight locomotive tires, car wheels. For rough tools, 
very heavy rails, heavy hanrl tools, wearing surfaces subject to 
rough usage. For axles, cranks, steel tires, cut gears. This is a 
very high grade steel when well made, deserving good treatment. 

(All forgings should be annealed to relieve internal stresses 
due to the hammer, for best service. "Soft" forging, however, 
as it is generally used for the less important work, is very often 
allowed to cool slowly without annealing). 



Table 


(15) 




STEEL CASTINGS 










"Add" 


C. 


Mn. 


P. 


s. 


Si. 




.27 


.68 


.066 


.047 


.261 


Mach'ry, boxes, spindles, cranes, etc. 


.25 


.72 


.057 


.048 


.261 


it 1 ( 1 1 It 1 1 


.28 


.66 


.043 


.043 


.30 


II II II II •« 


.45 


.74 


.040 


.044 


.295 


Mill crabs, cut gears, etc. 


.88 


.74 


.040 


.050 


.32 


Rolls (Hot Rolling). 


.87 


.74 


.039 


.037 


.30 


II II II 


.84 


.75 


.042 


.032 


.295 


" and special levers 


.95 


.72 


.035 


.042 


.28 


" " " castings. 


1.05 


.71 


.040 


.035 


.32 


Special, hard castings. 



Elongation in 2" (medium) over 17. 
Reduction of area over 24. 
Heats 1-3 are medium hard. 



18 



Table (16) HIGH CARBON STEELS 

"Basic" 

Si. 



c. 


Mn. 


P. 


S. 


.656 


.45 


.027 


.045 


.705 


.27 


.015 


.038 


.730 


.22 


.009 


.047 


.759 


.31 


.028 


.051 


.809 


1.10 


.016 


.040 


.850 


.27 


.029 


.041 


.869 


.50 


.020 


.046 


.909 


.45 


.035 


.031 


.955 


.23 


.011 


.052 


.972 


.26 


.009 


.036 


1.000 


.28 


.011 


.045 


1.014 


.24 


.009 


.036 


1.035 


.24 


.007 


.039 


1.074 


.27 


.012 


.036 


1.121 


.31 


.030 


.048 


1.140 


.32 


.012 


.051 


1.145 


.22 


.007 


.046 


1.162 


.29 


.007 


.038 


1.175 


.33 


.007 


.030 


1.216 


.33 


.015 


.040 


1.223 


.23 


.027 


.044 


1.286 


.30 


.007 


.049 


1.415 


.34 


.046 


.036 



Special tempered forging. 
.11 Crucible remelting, forgings. 

Special tempered forgings, springs. 
.15 " " " files. 

Tempered piston rod, engine valve 

stems. 
Crucible remelting; special shafting. 
Heavy springs, files. 
Springs and tools, wearing surfaces. 

'* " " heavy die blocks. 

files. 

" " " cutting tools. 

Anvil faces, die blocks. 
Springs, die blocks, files, 
tools. 

" wearing plates. 

Springs and tools, files. 



Special springs, files. 

Tools and springs, heavy wearing 
surfaces. 



Tools and springs. 



19 



'able (17) 






SPECIAL STEELS 














"Acid" 




T.S. 


C. 


Mn. 


P. 


s 


Si. 


Cu. Ni. 




89,960 


.28 


1.05 


.042 


.065 








86,420 


.28 


1.21 


.063 


.064 










.30 


1.20 


.066 


.060 








20,550 


.395 


1.34 


.070 


.060 










.342 


.76 


.053 


.035 


.31 


.45 3.43 "Nickel" 


' forging. 




.32 


.62 


.050 


.040 


.27 


.20 3.40 


4 1 




1.724 


17.75 














1.201 


10.67 














1.02 


12.54 













The first three heats are well adapted for cotton mill spindles 
which must be light, stiff, and capable of a smooth finish. These 
steels are suitable for axles, or for shafting requiring a smooth 
finish. For polished levers, hand rods, etc. The 4th heat is a 
stiffer steel for the same purpose. Any of these 4 heats are 
suitable for axles for buggy work; they take a smooth finish. The 
nickel heats are typical of this grade of steel; an excellent specifi- 
cation for nickel forgings. The last three heats are manganese 
steels for wearing surfaces such as railway cross ores, switch points 
and for grinding surfaces, stamping shoes, crushers, etc. They are 
hard to machine, requiring special high speed steels. 



20 



Table (18) 



CARBON STEELS 

"Crucible" 

(Tools for Cutting Purposes) 

These steels harden in water. 



Authority 


.No. 


C. 


Mn. 


P. 


S. 


Si. 


P 


1 


.32 


.60 


.035 


.019 




Howe 


2 


.55 






.260 




Taylor 


3 


.681 


.198 


.024 


.011 


.219 


P 


4 


.752 


.215 


.020 


.027 


.201 


P 


5 


.876 


.25 


.027 


.030 


.24 


Taylor 


6 


.992 


.318 


.037 


.020 


.256 


Taylor 


7 


1.047 


.189 


.017 


.017 


.206 


P 


8 


1.132 


.202 


.026 


.015 


.262 


Taylor 


9 


1.240 


.156 


.016 


.006 


.232 


P 


10 


1.412 




.021 


.011 




P 


11 


1.542 


.241 






.276 


Shore 


12 


1.65 










Shore 


13 


1.75 











Va. Cr. 



.08 



.079 



Welds 


Hardens 


with 


at P° 


ease 


1600 


' • 


1450 


1 < 


1450 


4 ( 


1425 


care 


1425 


' ' 


1420 


1 1 


1420 


great 




care 


1410 


great 




skill 


1400 




1395 




1390 




1385 




1385 



FOR 

1. Rough chisels, mauls, sledges, heavy hand tools, hammers. 

2. Stamping dies, boiler cups, chisels, hammers. 

3. Stamping dies, boiler cups, chisels, and lathe and planer 
tools. 

4. Stamping dies, boiler cups, chisels, and lathe and planer 
tools. 

5. Stamping dies, boiler cups, chisels, and cold sets and 
hammers. 

6. Stamping dies, boiler cups, chisels, and cold sets and 
hammers. 

7. Lathe and Planer tools, cold chisels and hot sets. 

8. Lathe and Planer tools, taps, screws, dies, etc. 

9. Lathe and Planer tools, taps, screws, dies, etc. 

10. Drills, saws, chilled roll tools, dies. 

11. Drills, saws, chilled roll tools, dies, razors, etc. 

12. Drills, saws, chilled roll tools, dies and for all very hard 
fine tools. 

13. Drills, saws, chilled roll tools, dies and for all very hard 
fine tools. 



21 



Table (19) CARBON ALLOYS 

"Crucible" 
These steels harden in water and in oil. 





















Hardens 




No. 


C. 


Mn. 


P. 


S. 


Si. 


W. 


Cr. 


at F" 


Taylor 


1 


.710 


.102 


.016 


.008 


.326 




1.773 


1420 


'• 


2 


.745 


.102 


.016 


.013 


.287 




1.631 


1420 


Shore 


3 


1.000 












3.50 


1400 


Taylor 


4 


1.220 


.300 


.017 


.010 


.180 


6.75 




1395 


' • 


5 


1.376 


.552 






.255 


1.842 




1390 



For — Lathe and planer tools, dies, drills, taps, cutters, saws and 
cutting tools. For special machinery, automobiles, etc. These are 
essentially tool steels. Steels of this kind, while carrying (W) and 
(Cr), or both, in small quantities, require the heat treatment of 
straight carbon steels. The alloys give Increased strength and 
resistance to shock, but do not in these quantities, render the steel 
" self -hardening. " Practice has shown that both (W) and (Cr) 
must be present in the proper quantities to make steels effective 
as a cutting medium at high temperatures — that is to make them 
"high speeds." (Mo) is sometimes used to replace (W). 



22 



Table (20) SPECIAL GEAR STEELS 

Acid Open Hecirth and Crucible. 



No. 


C. 


Mn. 


P. 


S. 


Si. 


Ni. 


Cr. 


Va. 


1 


.425 


.59 


,012 


.032 


1.98 








2 


.723 


.61 


.010 


.024 


1.95 








3 


.249 


.32 


.007 


.032 


.28 


2.95 


1.24 




4 


.112 


.35 


.007 


.052 


.18 


3.47 


.25 




5 


.101 


.29 


.007 


.024 


.30 


5.40 


1.80 




6 


.252 


.40 


.012 


.030 


.28 


4.95 


.92 


.10 


7 


.31 


.65 


.007 


.022 


.19 


3.20 


1.50 




8 


.52 


.32 


.012 


.031 


.22 


2.95 


.85 


,06 



These steels are suitable for very high grade cut gears, and 
machine parts that must be hard and very strong. Steel No. 7 
would probably have an ultimate strength of 135,000 pounds per 
square inch, with an elastic limit of 125,000 pounds. These are 
very special steels suitable for the more expensive machinery, as 
automobiles, flying machines, etc. These steels require very special 
hardening and tempering. Some of them are capable of air 
hardening, as shown by a later table. The first two are known as 
"silicon" steels; the balance as "chrome nickel" steels. All of 
these steels harden in water; 4 and 5 are best used in the natural 
state for vibrating or twisting parts of machinery. 

Nickel-chrome steels are best practice for heavily stressed 
members in bridge work, and a straight 3.50% nickel steel of about 
.35 carbon is also an excellent specification for very important 
work. Alloy steels, properly made, will take 10 to 12 times the 
number of twists that straight carbon steels will take in the 
flexure test. Their increased cost is more than offset by the 
resistance to shock, the decrease in weight of material necessary, 
and the great strength. 



23 



Table (21) 



SELF HARDENING 

"Crucible" 

These steels harden in air or in oil. 



Tay 



No. 


C. 


Mn. 


P. 


S. 


Si. 


W. 


Cr. 


-lor 1 


1.143 


.18 


.023 


.008 


.246 


7.723 


1.830 


2 


1.842 


2.43 


.023 


.007 


.890 


11.59 


2,694 


3 


2.150 


1.578 






1.044 


5.441 


.398 


4 


2.213 


1.800 


.037 


.023 


.883 


6.057 


.342 


5 


2.320 


3.530 


.036 


.004 


.630 


7.599 


.074 



These steels, experimented oh by Messrs. Taylor & White, and 
showing increased efficiency by the Taj'lor-White heat treatment, 
led to the manufacture of high speed Steels. These steels are tool 
steels, suitable for lathe and planer -work. They have been re- 
placed by high speed steels. 



Table (22) HIGH SPEED 

"Crucible" 
These steels harden in air or oil. 



C. Mn. P. S. Si. Mo. Va. W. Cr. 

*raylor 1 .682 .07 .049 .32 17.81 5.95 

.024 .016 .57 
.22 

.052 4.21 
.021 .014 .072 . .42 

These steels followed the self-hardening steels as the result of 
the Taylor-White discovery. All of these steels harden best in an 
air blast at 2100° to 2250° Fahr; or in oil; or in a lead bath 
after previous heating to the high temperature. 



24 



p 


2 


1.166 


.33 


Taylor 


8 


1.28 


.14 


1 1 


4 


.76 


.09 


P 


5 


.861 


.11 



15.64 


2.69 


19.97 


3.88 


13.44 


3.04 


17.21 


5.42 



HEATING 

In general, the lower the carbon is in steel, the higher the 
heat allowable. "Dead Soft Basic" works at a light yellow, while 
spring steel must not be rolled above a good red. The former will 
take heavy drafts, at its proper temperature; the latter must be 
worked down slowly. Between these extremes, in rolling mill, and 
forge practice, fine gradations are being made by steel workers. 
Heating is being studied as it has not been heretofore in mill prac- 
tice, and is given some of the attention that the tool steel workers 
long ago found so necessary. A fixed draft in a rolling mill demands 
a fixed temperature in heating; nor will the correct draft remedy a 
wrong temperature. As in forge practice the hammer man controls the 
effect of his hammer for various grades and temperatures of steel, 
so in rolling mill practice it is necessary for the roll designer to 
regulate the draft of his passes for various grades of steel at the 
correct temperature. *' Heating" and "working" must be ap- 
plied to steel scientifically — and "heating" so far, has received 
the less attention. 

Heating of crucible steels has received more study than has 
been given to open hearth or bessemer steels. This has been de- 
manded for the reason that high carbon steels are easily ruined 
and carbon steel was the first product of the crucible. Huntsman 
made crucible steel by remelting in graphite pots, bars of Swedish 
iron which had been "cemented" — i. e., had been heated bright 
red in closed boxes with alternate layers of charcoal. This was 
done about the middle of the 18th century and it is a generally 
accepted fact that crucible steel so made, possesses superiority over 
all others. In 1801 Mushet patented the process of melting in the 
crucible with Norway iron bars, "medicine" of carbon, etc., sav- 
ing the time and expense of "cementing." In 1868 E. F. Mushet 
invented the first of the air hardening steels melting the raw 
materials in crucibles. Since that time the process has not changed. 
Various grades of steel and various alloys are made in crucible pots, 
by either of the two mentioned methods. Huntsman's or Mushet 's. 

The discovery of the "Dull Red" temperature for hardening 
high carbon steels, and the various temper colors, was made many 

2S 



years ago. The information is much abused. "Dull Red" is not- 
easy to judge; some tool makers don't know it when they see it. 
In the temper colors some have favorites. It is a fact that every 
grade of steel has its best working temperature, best hardening 
temperature, drawing color and cutting speed, and any deviation 
from these best conditions means a loss to the buyer and user. 
Steel should be adapted to the purpose at which it is most efficient 
and the selection of tool steels for various purposes is a man 's job. 
Large users of tool steels carry on experimental work all the time, 
tabulating brands, prices, cutting angles, hardening temperatures. 
drawing colors, cutting speeds, wear, waste and outputs; small 
users would do well to pool their interests for the same purpose — 
for it is probable that about 3 to 4 times as much tool steel is 
made and sold as is needed to do the work now required to be 
done. Two-thirds, or more, is lost; wasted, burned, badly worked — 
and the price stays up. The first chance of error in treating tools 
occurs at the heating to work to shape. Carbon steel breaks down 
very quickly and it pays well to spend plenty of time and care in 
shaping tools under the hammer. Even in heating to cut off a 
section be careful to keep carbon steels below a "red." Keep at 
medium red, and cut slowly. 

High speed steels differ from Carbon steels in that they must 
always be worked at a high temperature, never below bright red. 
The bad effects of working high speeds at a low temperature equal 
those of working carbon steels at a high temperature. In their 
heat treatments, carbon steels and alloy steels (high speeds) are 
practically opposed to each other. 



26 



\ 



I30O 



CARBON CRUCIBLE STEELS 




16'eo Tahr. 

(shorb) 

Cut (4) shows the effect of hardening steels of various carbons, 
at different temperatures. Hardness by the Scleroscope, and rela- 
tive strengths and losses, are indicated by the figures at the left. 
The steels were tested to destruction by heating. These curves 
plainly indicate the effect of over heating to harden; they not only 
show a decrease in hardness when tested by the Scleroscope, but 

27 



/ 

indicate the weakness due to crystallization. The higher the 
carbon, the greater the loss due to any degree of super-heat. Note 
that the eifective temperature for 1.75 carbon steel is limited to 
a range of less than 15 degrees each side the proper one. A low 
carbon steel, (.32%), has been heated by the writer to 1800 °r. and 
hardened, without much loss in hardness or strength. This latter 
was low priced crucible steel intended for "chipping" chisels in 
foundry work. But this steel, if properly hardened, would not 
begin to do the work that the 1.75% carbon steel would, if both 
were properly worked or hardened. High carbon, high priced steel 
should be hardened at a dull red, never over 1400°F. It should be 
worked under 1500', very slowly, with many light blows, with con- 
tinual reheating as the temperature falls. 

Between the ranges of .32% and 1.75% carbon probably lie 
all the "Carbon" steels in general use. No matter what the 
carbon, the safe hardening temperature is below ISOCF. If a steel 
is low in carbon you do not lose much by over-heating; if a steel 
is high in carbon, .85% or over, you may lose the tool. It is 
understood that "over-heating" applies to steel that is about to 
be chilled in water. Steel must be heated to be shaped under a 
hammer, and a skillful smith, by rapid, light working, will prevent 
crystallization at a comparatively high temperature. But "bright 
red" is very hot for high carbon steels, and a rapid hammer is the 
only means of preserving the original quality of the steel. Work 
high carbon steels at a dull red, slowly, in shaping, for the best 
results. 

These curves illustrate the necessity of close attention to 
carbon steels; the more they cost the easier it is to spoil them; 
but, further, the higher the price of carbon steels, honestly made, 
and sold, the greater will be the return in service to the user, if he 
will do his share toward perfecting the process of making tools. 



29 



TEMPERING CARBON CRUCIBLE STEELS 




CUT 5 



1.50 aso 350 4io SSO 6S0 FRHR. 

(shore) 



Cut (5) is offered to indicate the care required in tempering, 
to obtain the desired results. The ordinates are degrees of flexure 

29 



obtained by loading the end of a rigidly held piece of the steel, 
of standard size, and noting the maximum deflexion from which the 
piece will recover when released. These ordinates indicate the 
relative strengths of the difl'erent steels, differently tempered. 
Note the recovery of strength after 535°r. at purple. In the table 
(below) the hardness at various temperatures is given; this hard- 
ness or cutting power, was determined by the Shore S'cleroscope. 



eTO-p 



75 



As hardness indicates strength, together with the flexure test, 
the superiority of No. 2, the 1.65% Carbon steel is apparent. Such 
a steel has no equal for a cutting edge, when properly treated. 

The following scale is of interest in determining the temper 
colors. 

Color. Fahr. 

First Color 430° 

Straw _, 450° 

Dark Yellow 470° 

Brown 495 ° 

Brown, purple flecked 510° 

Purple 535° 

Blue 560° 

Dark Blue 600° 





Kind of 








Hard 


ness at 




Curve. 


Steel. 




200°P 


470°F 


520''P 


540 °P 


600 °F 


No. 1 


Vanadium, 




80 


72 


69 


65 




No. 2 


Carbon, 


1.65% 


105 


101 


98 


94 


88 


No. 3 


' ' 


1.30% 


105 


100 


97 


93 


86 


No. 4 


Vanadium, 




92 


86 


84 


79 




No. 5 


Carbon, 


1.10% 


98 


95 


92 


85 


83 


No. 6 


« i 


.90% 


91 


85 


74 


73 





30 



15 



to 

















u 


^ 




^j^ 






' 




^ 


^ 


^ 


n 













loo ZW «O0 4«0 500 9O0 700 flOO 900 I0«l 1100 



CUT 6 



(shore) 



Cut (6) indicates, again, the loss in hardness and the great 

gain in strength obtained by tempering to various colors. The 
length of line indicates the limit of elasticity and is a measure of 
the strength. No. 5 will stand the most punishment; No. 1 un- 
tempered is brittle. The following table shows the hardness and 
cutting power at the various tempers. 



Curve. 


Kind of Steel. 


Color. 


T 


empeied at 


Hardness 


No. 1 


Carbon, 1.75% 


Hardened 






110 


No. 2 


( • t 1 


Yellow 




465°F 


104 


No. 3 


4 4 4 1 


Dark Brown 




525°F 


98 


No. 4 


4 4 it 


Dark Blue 




600 °F 


91 


No. 5 


t 1 ft 






650°P 


88 



Such a steel should be tempered to a yellow, 450°F. and used 
as a cutting tool receiving the minimum amount of shock. Note 
the hardness at a yellow temper; this is razor steel. Properly 
handled, its life would easily pay all the cost of manufacture for 
the most expensive cold die work. 

31 



'Jo 



ZS 



2o 



IS 



10 



1 






j 




Sj 


1 


/ 






1 








f 

/ 




1 


/ 








/I 




^/, 


^ 


/ 








1 / 


::y^ 


/^ 




^ 








^ 


^ 


:^ 







CUT 7 



(00 ^00 ^o 4oo '•S^fO ^0 7oo doo 900 iood jkm |2oo JdOd 

(shore) 



Cnt (7) shows a nickel steel, with chromium; a typical chrome- 
nickel steel. 



Curve. 


Condition. 


Hardness. 


Nickel 


4.40% 


No. 1 


Natural 


48 


Chromium 


1.53 


No. 2 


Tempered 535°F 


62 


Carbon 


.26 


No. 3 


Hardened 


75 







Hardness is sacrificed for a slight increase of ductility by 
tempering. Chrome-nickel steels possess great toughness, but do 
not have extreme hardness. They may be used to advantage with- 
out temper drawing, as curve No. 3 indicates; they show great 
resistance to repeated or dynamic shocks, whether "natural," 
"hardened" or "tempered." 



32 



3o 



as 



20 



ss 



10 





1 





/ 






1 










/ 


I 




p. 


/ 


^ 


■/ 




4- 








J 


^ 






^ 


















/. 




1. 


y 


^ 


















^ 


^ 


^ 


^ 

























100 ;{(w 400 400 -Sbo ««4 700 eao 9Qi tota nao naf 1300 Mi I6at 

PowNOd 

CUT 8 (shore) 

Cut (8) shows the effect of tempering a vanadium steel, for 
axles, to various colors. 



Curve. 


Tempered, F" 


Hardn 


No. 1 


Natural bar 


46 


No. 2 


600 


79 


No. 3 


520 


84 


No. 4 


470 


86 




Hardened 


92 



The remarkable strength indicated by curve (4) is typical of 
vanadium steels, well made. It requires careful handling. 

All of these curves show the need of care in handling high 
priced steels. Steel is spoiled in the heating process more easily 
than by any other treatment. Conditions and appliances which 
regulate the treatment and perform the work, are absolutely neces- 
sary. "Guessing," too much 
lators. 

33 



"experience," are not heat regu- 



In ordering crucible steels tliat are to be machined to size 
before being heat-treated, always specify sizes that will allow 
the removal of the outer skin and scale. This is absolutely neces- 
sary, both in carbon steels and in high speed alloys. The following 
scale is suggested. The allowances are liberal, but it is intended to 
avoid bad products at the comparatively small expense of addi- 
tional steel and the cutting to shape. Annealed bars_generally lose 
in hardness and bars of all shapes are generally less hard on the 
exterior than below the skin, after being heat-treated in the natural, 
or rolled or hammered size. 

Nominal Sizes (inches).. 1 m 2 2 V2 3 BV2 4 41/2 5 6 7 

Specify for Rounds 1^ 1 ^j 2% 2% 3^ 3^ 4V4 4% 5% 6^ 7% 

Specify for Squares 1% 1% 2ft 2^ 3% 3% 4^^ 4% 5% 6ft 7% 

In the long run it pays to state the use to which steel is to be 
put and to let the maker determine the grade or size, as in the 
above table. Tool steel makers receive complaints from users; 
the user hears the complaint of his own tool nmaker. The chances 
for advancement in knowledge, from experience, lie with the man 
that makes the stuff. Some ste«l plants are over 100 years old; 
their letter files would probably make a valuable text-book of tool 
steel specifications. 



HIGH SPEED STEELS 

The treatment of "Self -hardening" steel is not offered. It 
may be stated that any alloy steel requires careful treatment, es- 
pecially those in which chromium, vanadium, or tungsten are used 
to increase the strength due to carbon. When a "Self- hardening" 
steel carries sufficient Tungsten and Chromium to advance it into 
the ' ' High Speed ' ' grade, it becomes a member of that grade, as 
the Taylor-White discovery showed. 



34 



HARDENING HIGH SPEED STEELS 

These directions are intended to be explicit; each item ia im- 
portant. 

(1) Cut tool lengths from the hot bar— at red (1700°F.) or 
higher. Do not cut bars cold by nicking and breaking. Annealed 
bars may be cut by power-saw or in a lathe, but at a slow speed. 

(2) Heat the steel in a clean fire, without blast, until the 
piece is thoroughly heated; increase the blast until the steel be- 
comes very bright red, nearly yellow. Commence to forge; when 
the temperature falls below a medium (1700°) red, reheat as be- 
fore. Do not work this steel below a medium red, and preferably 
not below a bright red. 

(3) When the tool is rough forged, cool slowly in a dry place. 

(4) For convenience, grind the forged tool to the approxi- 
mate shape desired, but not to the finished shape, on a dry stone. 
This is optional; stock must always be left at the cutting edge, 
(1-16" to 3-16") to allow for hardening. 

(5) Having followed 3 (or 4), to harden, heat slowly in a 
cllean fire to a Bright Red, then more rapidly to a White Heat, 
dazzling white; withdraw from the fire and cool in a strong cold, 
dry, air blast. (Rape, whale, or cotton seed oils may be used for 
cooling, but air is the best). 

(6) Grind the tool carefully, by hand, on a wet sandstone or 
emery. Use care in grinding or the steel will heat to the annealing 
temperature and lose its cutting power. 

The foregoing directions are complete for all high speed steels 
and if followed will give the best results that any steel will give, 
regardless of its brand, if it be a true high speed steel. Leave 
plenty of stock at the cutting edge; if the extreme edge begins to 
"run" when being heated to harden, and the whole nose of the 
tool is thoroughly and strongly heated, the hardening effect will 
be at its maximum. The tool sheuld be hot from lip to heel, and 
back to the shank, A coke fire for hardening is the best; there 
should be plenty of fuel on the tuyere and a good strong heat. 

35 



Mr. Taylor recommends a second or low heat treatment for 
high speed steels, substantially as follows: 

(1) Reheat the already hardened tool slowly, preferably in 
a coke fire, not to exceed 1200°F. and place in a lead bath of at 
least 3600 pounds weight, which is rigidly maintained at a tem- 
perature of 1150°F, 

(2) Allow the tool to remain in the lead bath not more than 
5 minutes, remove and cool in the air blast, as before. Care must 
be taken that the temperature of the previously hardened tool 
does not go above 1240°F,, the breaking down, or annealing tem- 
perature. 

If a tool is accidentally so heated in the process of manufac- 
ture, it should be heated as stated above, for hardening, worked 
lightly with hammer, cooled slowly, and again brought to the 
hardening heat (2200°F.). The object of the second low heat 
treatment appears to be the removal of internal stresses and to 
make the hardening effect more uniform. 

IS 



IQ 





^. 


z^ 




A 


A 


f 






^ 




^ 




0" 















p^jy^ /OO ?00 ^?0O Ana SOQ 600 'XOQ 000 900 



CUT 9 



(shore) 



Cut (9) indicates the hardness, elastic limits and strengths of 
a sample of high speed steel heated to various temperatures, hard- 
ened by different means, and in two cases "tempered." 



36 



Curve. 


Hardened at 


Hardened in 


"Tempered." 


H 


ardncss 


No. 1 


2250°P 


Oil 






99 


No. 2 


Rolling Heat 


Air 






101 


No. 3 


2150°F 


Oil 


650°F 




95 


No. 4 


2000°P 


Air 


650°F 




94 


No. 5 


2150°F 


Air 






99 


No. 6 


2100°F 


Air 






90 



Generally, high speed steels are not tempered. The reheating to 
650"F. above a blue, indicates a temperature at which this particu- 
lar brand held its hardness or cutting power. This grade of steel, if 
held at this temperature, and cooled very slowly would show ex- 
ceptional resistance to dynamic shock and would prove very valu- 
able for such purposes. Note the loss when hardening at lower 
temperatures. "Tempering" having been carried further as in 
the low heat treatment, Taylor-White process, up to 1150° and 
then cooled in air, a return of hardness would probably have taken 
place. This steel is about as hard as the usual 1.20% carbon steel 
hardened at 1400°F. It is very much stronger than the carbon 
steelj will stand shocks better and is in general the superior tool 
for cutting purposes. A very high carbon steel, however, takes 
precedence for slightly smoother cutting edges, greater hardness 
and sufficient strength for the purpose where it is not shattered by 
heavy work. High speed will cut at a temperature of 1000°F. and 
over where carbon tempered steels are useless. 

COMPARISON. 

The very best carbon steel made today is worth 40 cents per 
pound; this steel is unequalled, but it requires experience, skill and 
absolute adherence to the laws for shaping, finishing, hardening and 
tempering. The best high speed steel sells for $1.20 per pound. 
As cutting tools, those two steels are hard to compare. The 
high speed will not take the edge that can be given the 
carbon steel; it will not take the smooth finish, is not so suitable 
for fine cold die work, for which the carbon steel is excellent, nor 
will it cut chilled rolls so smoothly. But if tools of these two 
steels are shaped, and heat-treated, each to its best, for lathe work, 
the high speed steel would give 10 times the yield. Further it 
wouJd cost less to work into a tool, both bars being the same size, 

37 



since the high speed steel is worked at a high forging heat. For a 
"glass finish," for hardness when cold, a keen edge, and smooth- 
ness the carbon steel is the better, and is in fact unsurpassed. 
For ease of hot working, cutting power at high speeds and tem- 
peratures, resistance to shock, toughness, wearing power, ability to 
recover when over-heated (by reheating) the high speed steel is 
4 to 10 times better than any carbon steel. 

Carbon steels range in price from 5 cents per pound to 40 
cents per pound. "High Speeds" from 55 cents to $1.25. For 
lathe, planer and boring mill roughing tools, for cutting in fact, 
the 55 cent steel is 4 to 8 times as effective as the very best 
carbon steel. There is no comparison between the two steels for 
this purpose. 

Very slowly the high speed steels are replacing the carbon 
steels for dies, especially in "hot" work, for bolts and rivets. 
The user should bear in mind the fact however, that high speed 
steels do not harden to the degree that carbon steels do. If the die 
must be very hard, carbon steel is the thing; if it must be only 
relatively hard, must hold its hardness when hot, say 1000°F. and 
must above all be strong, high speed alloys are the best. The table 
on page 35 shows the hardness of High Speed steels; soft steel on 
the same scale is about 35 hard, while the best carbon steels will 
show 110, when hardened. 

All grades of steel have been tried both in carbon and high 
speeds for hundreds of purposes. The very best shops continue and 
will continue to try and there are three very good reasons: 

(1) The trials made for some reason or other are incorrect 
and not authoritative; for want of time, or because of material, 
or error, or exact comparative data, 

(2) Steel continues to improve in quality; the demands on it 
continue to increase; the user's knowledge grows, as witness the 
employment of steel experts. 

(3) The progressive man is always trying according to his 
judgment. 

3A 



HIGH SPEED STEELS 

The manufacture of High Speed steels entails all the expense 
of carbon steels with the additions of the cost of the raw materials 
and the skill in balancing the alloys so that hardness or cutting 
ability may be obtained and retained at a high temperature. 
Tungsten is expensive, as are chromium and vanadium. Unless the 
product is correct in analyses the whole melt is lost; in the carbon 
steels an incorrect analyses for one grade may be a correct one for 
another. High speed steel makers have two or three brands on 
which to apply their steels; carbon steel makers have a dozen. 

While high speed alloys are mainly used at present for rough- 
ing tools, and for dies, etc.. in hot work, there is nothing to prevent 
their use for finer tools. There is a tendency to believe that high 
speed steels are not effective unless heated to a temperature that 
destroys the shape of cutters, drills, etc. This is not true. It is a 
fact, however, that when heated to 2200°F. they are hardest; it is 
also a fact that they are exceedingly hard when cooled from a 
lower temperature, and they are very strong. If then, a tool made 
of a high grade alloy be hardened in oil from a temperature of 
1900° there will result a cutter that will stand up under heavy 
work, that will give an increased yield, especially if run with 
water, and will be capable of cutting much faster than a carbon 
tool. As stated before, for very keen edges with absence of shocks, 
and for hardness, together with price, the carbon steel is preferable; 
for heavy work of all kinds, for speed, rough handling under severe 
conditions, long life, certainty of yield of labor applied to it, the 
higher priced, well made alloy is the best. It is the more efficient 
product. 



39 



THE RANGE IN CUTTING SPEEDS 

This table is made up of data taken from F. W. Taylor's book 
"On the Art of Cutting Metals" and aims to show the possibili- 
ties of high speed steels as well as the existing facts. The tables 
and numbers referred to are those on pages 19 to 22, the figures, 
feet per minute. 

Table (23) 



Table. 


No. 


Forgings. 


Forgings. 


Hard Iron. 


Cast Iron. 


Kind of Steel. 


18 


3 








47' 


Carbon, tempered 


18 


6 


165^' 






48' 


1 1 • i 


18 


7 


16' 


6' 




47%' 


■ « * I 


18 


9 


16' 


6' 




47' 


« « II 


19 


1 


18' 


7' 




71' 


Carbon, chrome 


21 


1 


25%' 


12' 




89' 


Self hardening 


21 


3 


25' 


7%' 




86' 


II 11 


22 


3 


84' 


38' 






High speed 


22 


4 




37' 


45%' 




1 ( 4 1 


22 


1 


99' 


41%' 


52' 




II II 



The following ratios of cutting eflfieiencies developed since 1906, 
as shown by practical experiment and shop work, are of interest- 
Relative values of High Medium Hard Hard Soft 

Speed Steel over Steel. Steel. Cast Iron. Cast Iron. 

Carbon (tempered) 6 to 7 7 to 8 3 to 4 3 to 4 

Carbon Chrome (tempered) 5% 6 3 to 4 3 to 4 

Self Hardening 3 to 4 5 2 2 to 3 

Or, assuming high speed steel 100% efficient, self-hardening 
steel is 30% efficient; carbon chrome-tungsten is 20% efficient; 
carbon steel 15%) efficient. 



40 



The analyses of "medium" and "hard" steel and "hard" 
and "soft" cast iron are important, and Mr. Taylor's classifica- 
tions are given below, as used by him. 



Medium Steel Forgings. 



Hard Steel Forgings. 



Carbon 


.34 


1.00 




Manganese 


.54 


1.11 




Silicon 


1.76 


.305 




Phosphorus 


.03 7 


.036 




Sulphur 


.026 


.049 




Tensile strength 


70280 


91670-101860 


(each end) 


Elastic limit 


34630 


60090-53980 


(« 1 « 


Percent of extension 


29 


7-5 


• « II 


Percent of contraction 


44.34 
Hard Cast Iron. 


11.66-9.73 


1 1 II 


Carbon, Total 


3.32 




Combined 


Carbon 


1.12 




Manganese 




.68 




Silicon 




.86 




Phosphorus 


.78 




Sulphur 




.073 





"Medium" and "hard" steel forgings are shown in tables 
(12) and (13) of this book. 



44 



The following speeds, based on observation, may be expected 
with the best modern high speed steels that have been properly 
worked and heated. 

Table (24) 



Material. Depth. 

Soft Cast Iron Vi 

y* 

Soft Steel Forging V4, 

V* 

^ 



Medium 
Hard 



Very Hard 



y* 

% 

y* 

y* 

Hard Cast Iron •?« 

Wheel Tires % 

Manganese Steel % 



Feed 


Speed, Ft. 


Per Min 


% 


100 to 


150 


A 


125 to 


175 


% 


100 to 


150 


A 


125 to 


200 


■h 


80 to 


125 


^ 


80 to 


100 


t\r 


70 to 


90 


% 


50 to 


80 


T^ 


40 to 


60 


% 


30 to 


50 


t^ 


40 to 


60 


% 


20 to 


30 


^ 


8 to 


20 



42 



SHAPING 

Cuts 10 to 15, show the best, simplest and cheapest forging 
methods for solid tools. As much work as possible is done under 
the hammer to save dangerous and expensive grinding. These are 
high speed roughing tools. 




CUT 10 (taylor) 

Heat to bright red and turn tip on anvil to about 80 degrees. 



43 




CUT 11 



(taylor) 



Draw down strongly at the heel, using a light steam hammer. 
Trim level on bottom. Trim on front to maintain angle of about 

80°. 



44 




CUT 12 



(taylor) 



Trim top, at nose, for back and side slopes. 



45 




CUT 13 



(taylor) 



Trim for clearance. Ronnd into shape, smooth up; use a cone 
gauge. Rough grind at this point, and heat to high temperature 
for hardening, about 2200°F. At this point a dry stone may be 
used in grinding. 



46 




CUT 14 



\taylor) 



Grind to shape desired on wet stone, with proper clearance, 
back slope and side slope at the cutting edge. 



i. ■ .3 



47 




CUT 15 



(taylor) 



The tool, finished, from the front. In forging reheat as many- 
times as necessary, keeping the temperature always above medium 
to bright red. 



48 



Cut (16) shows the manner in which extra stock is left at 
the tool point, not only to afford a means of noting the hardening 
heat, but to give metal for grinding to arrive at the proper cutting 
angles. For hardening, if the dotted point begins to "run" and 
the whole nose of the tool is hot, the temperature is at its b<<flt. 




CUT 16 



(taylor) 



49 



I 



Cuts 17 and 18 show the best radii for cutting edges for round 
nose roughing tools. These tools will take the maximum cut and 
feeds with the least amount of pressure and the least ' ' chattering. ' ' 




CUT 17 



(taylor) 



BLUNT TOOL 

For Cutting Hard Steel and Cast Iron. 

Clearance 6° 

Backslope 8° 

Sideslope 14° 

Radius of Point = iA-3\ 

50 




CUT 18 



(tavlor) 



SHARP TOOL 
For Cutting Medium and Soft Steel. 

Clearance 6° 

Backslope 8° 

Sideslope 22° 

Radius of Point = JA-i^e 

The best shape of stock for stiflf tools is that in which the 
depth is IVa times the width, or for a 1" tool we have a bar iy2"xl". 
There are exceptions in boring mill tools where squares and rounds 
are used to advantage. In boring mill ttools, care should be taken to 
maintain the proper angles. 

51 



Cut (19) serves to indicate a means of obtaining a cutting 
edge for special tools. The face of the tool is hollow ground on a 
small stone. The machinist who uses this method claims good 
results. He rough forges the ' * cup ' ' during the shaping up with a 
ball and has little grinding to do. It is a very simple and effective 
means of obtaining the proper angles, a circular template of the 
proper diameter giving the correct slopes for any given width of 
face. Such a method is excellent for small standard tools of ex- 
pensive carbon or alloyed steels having a fixed amount of cutting 
to do on the casting to which they are applied. Planer and shaper 
tools, finishing out recesses, bearing seats, etc. to size, can be 
shaped and finished in this way with excellent results. The use of 
a cupping ball by the blacksmith will carry out this idea in many 
tools. The cut shows a "hollow ground" cutter of the usual type. 
This is a principle that may be applied to other cutting tools to 
advantage. One of the advantages claimed is the breaking of the 
chip, due to the action of the ' ' cup ' ' or concave face. A roughing 
tool, cupped out in this manner will travel in either direction; 
this method is not recommended, however^ for heavy roughing work. 




CUT 19 



(taylor) 



52 



In general, the better man will develop more returns from the 
cheaper priced steels than will his competitor; but the better 
maker of tools of all kinds will buy the highest priced steel that 
his average of accidents will permit. In a word, he saves time by 
using more expensive steels than his competitor, when he knows 
how to handle them better. 

Usually the labor of shaping the steel exceeds the cost of the 
material. In the case of dies the labor cost may be easily 400 to 
500 times the cost of the steel. Kelatively. the steel cost in such 
a case is of no importance. Another factor always enters here 
however; mainly, the ability to work the high-priced steel without 
injuring it. It is easy to show in hundreds of shops by handing a 
blacksmith two pieces of carbon steel shaped alike, one worth 4 
cents and one worth 40 cents a pound, that the 4 cent steel is the 
one to use, in that shop. The 40 cent steel fails because it gets a 
4 cent treatment — and the trouble all comes in the heating. In the 
high speeds, in the same way, the 50 cent alloy wins out over the 
$1.00 alloy; but here the trouble comes from working at a low 
temperature, below 1500°, or not heating hot enough to harden, or 
grinding on a dry stone and annealing the point at 1240°. It is a 
fact that reputable makers grade steel to a nicety; it's up to the 
mechanic to take advantage of what the steel maker knows about 
heat treatment. 

A good sensible way to look at tool steel is from a basis of rel- 
ative cost — material to labor. If we have. 

Steel at $ 4.00 

Labor at 400.00 

Cost of die $404.00 

We can afford to pay 

Steel $ 8.00 

Labor 400.00 

Cost of die $408.00 

increasing the cost, 
by less than 1% and, in many cases, doubling the yield — provided 

53 



we do not injure the $8.00 steel. If, however, the $4.00 steel will 
make what we have to make, aad becomes scrap afterwards, it is 
the steel to use. 

Grading steel is a science in itself. The group of men with the 
greatest knowledge in this regard are the steel makers. Each user 
is one factor on the opposite side, studying his own problem, taking 
advantage of his own experience, but rarely getting accurate 
knowledge of his competitor's methods, or of any other methods. 
This booklet aims to show the need of co-operation probably 
through the press, with the best information coming from the man- 
ufacturer. It indicates the precision, the care, the thought, that 
goes into specifications and the treatment of steel, and aims to 
help the user to take care of the most serviceable metal we have, 
rather than to waste it. 



$4 



TO HANDLE TOOL STEELS 

1. Never nick and break cold bars. 

2. Work high speeds at a yellow, never below red. 

3. Harden high speeds at a white heat. 

4. Never heat a carbon steel above bright red, no matter how 

little it costs; never heat a 40 cent carbon steel above 
medium red. 

5. Water on the point when cutting increases the power of high 

speed tools by 20%. 

6. Water on a red hot high speed steel may ruin it. 

7. Heating high speed steel above 1240°, as in dry grinding, 

destroys its cutting power; it is necessary to go through the 
hardening process again. 

8. Air is best for hardening high speeds; use oil when hardening 

for taps, drills, dies, etc., at a lower temperature. 

9. Be careful in using a bath; too long exposure, or too high 

temperature by a very small margin, makes you reharden. 

10. For roughing tools, the cutting angles given in this book are 

probably the best. It takes care to keep them always the 
same; but it pays to be careful. 

11. Select your steel; keep a record. 

12. Grind wet, to finish; grind dry (high speeds) before you 

harden, 

13. Any good high speed will deliver red-hot chips; but you will 

generally find that the tool that does so in trial was ground 
by the salesman. He merely gets the best out of his prod- 
uct. Do you? 

14. Don't grind a high speed twist drill on a rough dry stone. 

just because it is a wonderfully strong tool. The steel in 
some of these drills cost $1.25 per pound. 

15. Make a gauge of two pieces of No. 10 sheets, slotted, with a 

thumb screw to hold them. Let the vertical piece slope on 
one edge to 6* clearance, and mark off back and side slopes 
with a scratch. You can grind correctly with such a gauge. 

55 



JUL 



o 



1 V( * ^-^ 



One copy del. to Cat. Div. 



■ JgA^r^i 



